So, I am working my way through all things KiCad and I found an issue on my (VERYOLD) nightly.
In PcbNew I set the page layout from the default, to "USLetter 8.5x11in".
The upper left corner was 0,0 ,,, but the lower right corner was NOT "dx 11.0 , dy 8.5"...
I hit "F9" followed by "F11" and all went back to normal again.
I can NOT (yet) replicate this bug; although I was staring at it trying to figure out why this is happening.
AND, YES, I HAD SIMILAR ISSUE MORE FREQUENTLY WITH THE STABLE 4.0.5.